Cryoablation devices and related methods for extending lifetime of heater in cryoprobe

Abstract

Embodiments of the present disclosure relate to cryoablation devices and related methods that extend the lifetime of a heater in a cryoprobe. A cryoablation device includes a cryoprobe having a heater and one or more sensors, and a cryogenic controller having at least one processor and memory. The refrigeration controller is configured to obtain refrigeration probe operating information characterizing one or more operating characteristics of the heater, compare the refrigeration probe operating information to a predetermined operating level of the heater to detect when a heater event occurs, and adjust a power signal supplied to the heater when the heater event is detected.

Description

Technical Field

[0001] This disclosure relates to a cryoablation apparatus and related methods for extending the lifespan of heaters in cryoprobes. Background Technology

[0002] This section provides background information in connection with this disclosure, which is not necessarily prior art.

[0003] Systems and methods for delivering cryoablation therapy may include a cryoablation probe introduced at or near a target tissue within a patient's body. The cryoablation system may include an extremely cold refrigerant (liquid, gas, or a mixture thereof) that can pass through the probe into thermal contact with the target tissue. Heat from the tissue is transferred from the tissue, through the probe, and into the refrigerant that removes heat from the target tissue. This removal of heat causes the tissue to freeze, resulting in destruction of the target tissue. It is desirable that the refrigerant have a sufficiently low temperature to freeze the target tissue rapidly and effectively.

[0004] It may also be desirable to keep the size of the cryoprobe needle small in diameter or outer contour to ensure accurate insertion into the patient to target abnormal tissue while avoiding damage to healthy tissue. Maintaining a small needle outer diameter and still including desired components within the needle for cryoablation or related procedures may be challenging. Therefore, improved cryoablation devices and related methods are needed to overcome the shortcomings of existing cryoablation systems and methods. Such improved devices and methods could provide more robust systems and methods, despite challenges in maintaining a sufficiently small cryoprobe diameter. Summary of the Invention

[0005] This section provides a general overview of this disclosure and is not a full disclosure of its entire scope or all its features.

[0006] In various embodiments of this disclosure, a cryoablation apparatus is provided. The cryoablation apparatus may include a cryoprobe comprising a heater and one or more sensors, and a cryocontroller having at least one processor and a memory. The cryocontroller may be configured to acquire cryoprobe operating information characterizing one or more operating characteristics of the heater, compare the cryoprobe operating information with a predetermined operating level of the heater to detect when a heater event occurs, and adjust the power signal supplied to the heater when a heater event is detected.

[0007] In one respect, the heater can be configured to raise the temperature of the cryogenic probe to 80 degrees Celsius or higher.

[0008] On the other hand, one or more operating characteristics of the heater may include the heater's resistance.

[0009] On the other hand, the heater can be positioned inside the needle of the cryoprobe.

[0010] On the other hand, the heater can be positioned on or inside the housing of the needle of the cryoprobe.

[0011] On the other hand, the predetermined operating level of the heater can be an upper resistance threshold and a lower resistance threshold.

[0012] On the other hand, the step of comparing cryoprobe operation information with a predetermined operation level may include determining a cryoprobe operation index and comparing the cryoprobe operation index with one or more predetermined operation index distributions.

[0013] On the other hand, one or more predetermined operating index distributions may include at least two predetermined operating index distributions.

[0014] On the other hand, at least two predetermined operating index distributions may include a first predetermined operating index and a second predetermined operating index, wherein the first predetermined operating index characterizes the baseline resistance of the heater and the second predetermined operating index characterizes the resistance of the heater under short-circuit conditions.

[0015] On the other hand, heater events can include one of the following conditions: short circuit, open circuit, or fault.

[0016] On the other hand, the step of adjusting the power signal supplied to the heater may include reducing the power signal to the heater when a heater event is determined to correspond to a short circuit condition.

[0017] On the other hand, the refrigeration controller can be further configured to continue the operation of the heater when the refrigeration probe operation information indicates that the heater has returned to the baseline operating condition.

[0018] On the other hand, when the refrigeration probe operation information indicates that a heater malfunction has occurred, the refrigeration controller can stop the operation of the heater.

[0019] On the other hand, the refrigeration controller can be further configured to send a notification when the refrigeration controller detects a heater event.

[0020] In some embodiments of this disclosure, a method is provided for operating a heater of a cryoprobe. The method may include acquiring cryoprobe operation information from one or more sensors of the cryoprobe, comparing the cryoprobe operation information with a predetermined operating level of the heater to detect when a heater event occurs, and adjusting a power signal supplied to the heater when a heater event is detected.

[0021] In one aspect, the step of comparing cryoprobe operation information with a predetermined operation level may include determining a cryoprobe operation index and comparing the cryoprobe operation index with one or more predetermined operation index distributions.

[0022] On the other hand, one or more predetermined operating index distributions may include at least two predetermined operating index distributions.

[0023] On the other hand, at least two predetermined operating index distributions may include a first predetermined operating index and a second predetermined operating index, wherein the first predetermined operating index characterizes the baseline resistance of the heater and the second predetermined operating index characterizes the resistance of the heater under short-circuit conditions.

[0024] On the other hand, heater events can include one of the following conditions: short circuit, open circuit, or fault.

[0025] On the other hand, the step of adjusting the power signal supplied to the heater may include reducing the power signal to the heater when a heater event is determined to correspond to a short circuit condition.

[0026] Other applicable areas will become apparent from the description provided herein. The descriptions and specific examples in this overview are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0027] The accompanying drawings described herein are for illustrative purposes only, representing selected embodiments and not all possible implementations, and are not intended to limit the scope of this disclosure.

[0028] Figure 1 This is an illustration of an example cryoablation apparatus according to some embodiments of the present disclosure.

[0029] Figure 2 This is an illustration of another example cryoablation apparatus according to some embodiments of the present disclosure.

[0030] Figure 3 This is a side cross-sectional view of an example cryoprobe according to some embodiments of the present disclosure.

[0031] Figure 4 This is a side cross-sectional view of another example cryoprobe according to some embodiments of the present disclosure.

[0032] Figure 5 This is a side cross-sectional view of another example cryoprobe according to some embodiments of the present disclosure.

[0033] Figure 6 This is a side cross-sectional view of another example cryoprobe according to some embodiments of the present disclosure.

[0034] Figure 7This is a graph illustrating heater resistance data and heater power signal data during an example heater procedure, illustrating aspects of this disclosure.

[0035] Figure 8 This is a graph illustrating signal pattern indices that can be used to detect heater events according to some embodiments of this disclosure.

[0036] Figure 9 This is an illustration showing an example machine learning model that can be used in some embodiments of this disclosure.

[0037] Figure 10 This is a flowchart illustrating an example method for operating and monitoring a cryogenic probe heater according to some embodiments of the present disclosure.

[0038] Figure 11 This is an illustration of an example computing device that can be used in some embodiments of this disclosure.

[0039] The corresponding reference numerals indicate the corresponding portions of several views that run through the accompanying drawings. Detailed Implementation

[0040] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0041] The provision of exemplary embodiments makes this disclosure thorough and fully conveys its scope to those skilled in the art. Numerous specific details, such as examples of specific components, devices, and methods, are set forth to provide a thorough understanding of embodiments of this disclosure. Those skilled in the art will understand that the specific details are not required, that exemplary embodiments may be embodied in many different forms, and that none should be construed as limiting the scope of this disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known techniques are not described in detail.

[0042] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may also be intended to include the plural forms unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having” are inclusive and therefore specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein should not be construed as necessarily requiring them to be performed in the specific order discussed or illustrated, unless specifically identified as such. It should also be understood that additional or alternative steps may be employed.

[0043] When an element or layer is referred to as “on top of,” “joined to,” “connected to,” or “coupled to” another element or layer, it may be directly on, joined to, connected to, or coupled to the other element or layer, or there may be intermediate elements or layers present. In contrast, when an element is referred to as “directly on another element or layer,” “directly joined,” “indirectly connected,” or “directly coupled to” another element or layer, there may be no intermediate elements or layers present. Other terms used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0044] Although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as “first,” “second,” and other numerical terms used herein do not imply sequence or order. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed below may be referred to as a second element, component, region, layer, or segment.

[0045] For ease of description, this document uses spatial relative terms such as “inside,” “outside,” “below,” “below,” “lower,” “above,” “upper,” etc., to describe the relationship between one element or feature and another element or feature as shown in the figure. In addition to the orientation depicted in the figure, spatial relative terms may be intended to cover different orientations of the device during use or operation. For example, if the device in the figure is flipped, an element described as “below” or “below” other elements or features will be oriented as “above” other elements or features. Therefore, the example term “below” can cover both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein can be interpreted accordingly.

[0046] In some embodiments of this disclosure, a cryoablation apparatus is provided for performing cryoablation therapy. The cryoablation apparatus may include a heater for performing needle repositioning and / or cauterization procedures during cryoablation therapy. The cryoablation apparatus may utilize the structures and methods further described in U.S. Application No. TBD by Varian Medical Systems, filed on the same day as this application, entitled “CRYOABLATION APPARATUSES AND RELATED METHODS FOR NEEDLE REPOSITIONING,” the entire contents of which are hereby incorporated by reference.

[0047] The heater that can be used in the cryoprobe of this disclosure may include one or more resistance wires of varying lengths, which can be heated when current flows through them. The power supplied to the heater may be sufficient to raise the temperature of the cryoprobe to 80 degrees Celsius or higher and maintain that temperature for approximately 5 to approximately 20 seconds. To accommodate the heater within or on the cryoprobe without increasing the overall size of the cryoprobe needle, the resistance wire of the heater may be a wire with a small total diameter. Due to manufacturing variations, the wiring of the resistance heater may be prone to failure or short circuits. Some failures or short circuits in the heater wiring may cause pauses in cryoablation treatment. Therefore, it is desirable to detect such occurrences during use of the cryoprobe heater and to take steps to prevent or minimize the likelihood of short circuits or failures that could cause pauses in cryoablation treatment.

[0048] The cryoablation apparatus and related methods disclosed herein can monitor the use and performance of the heater in the cryoprobe to detect when a short circuit or malfunction occurs. The cryoablation apparatus and related methods can also determine the operating condition, which can be used to extend heater life and allow cryoablation treatment to continue without interruption. In some cases, the cryoablation apparatus and methods can also determine if the cryoprobe is damaged or in a condition where cryoablation treatment should be paused and the cryoprobe discarded or repaired.

[0049] Now for reference Figure 1An example cryoablation apparatus 100 is shown. The cryoablation apparatus 100 may include a cryoablation console 102 and a cryoprobe 112. The cryoablation console 102 may include a cryocontroller 104, a refrigerant delivery device 106, and a refrigerant source 108. The cryocontroller 104 may include a computing device or other controller that can be used to control the delivery of refrigerant from the refrigerant source 108 to the cryoprobe 112 using the refrigerant delivery device 106. The refrigerant source 108 may be a suitable Dewar flask or other container that can be filled with refrigerant. The refrigerant delivery device 106 may include a pump, one or more valves, and other suitable fluid delivery devices to fluidly connect the refrigerant source to the refrigerant line 110 of the cryoprobe 112. Upon initiation of a freeze cycle, the cryocontroller 104 may cause the refrigerant to move through a refrigerant flow path that includes a refrigerant supply line from the refrigerant source through the refrigerant line 110 to the cryoprobe 112. The refrigerant may then flow back to the refrigerant source via a refrigerant return line or may be discharged using a suitable drain valve.

[0050] The refrigerant line 110 may be a flexible tube or other conduit that may include multiple lumens to allow refrigerant to flow toward the cryoprobe 114 in the supply direction and separately away from the cryoprobe 114 in the return direction. The refrigerant line 110 may be of sufficient length to allow the console 102 to be positioned near the patient in the treatment room and to allow the patient to be moved into and out of the imaging equipment. In some examples, the refrigerant line may be at least about 12 feet long. In other examples, the refrigerant line 110 may have other lengths.

[0051] A refrigerant line 110 fluidly couples a refrigerant source 108 to a cryoprobe 112. The cryoprobe 112 may include a needle 114. The needle 114 may be a pointed cylindrical tool or other elongated member configured to be inserted into and positioned at or near a target tissue during treatment. The needle 114 may be configured as a pointed tool having an outer diameter ranging from about 1 mm to about 4 mm. The cryoprobe 112 may also include a handle 116. The handle 116 may be configured with a first (or proximal) portion 118 and a second (or distal) portion 120. The first portion 118 may be substantially aligned with the refrigerant line 110, and the second portion 120 may be offset at an angle relative to the first portion 118. The offset angle between the first portion 118 and the second portion 119 may be about 90 degrees to define a right-angled handle. In other examples, the first portion 118 and the second portion 120 may be offset at different angles.

[0052] In some examples, the handle 116 may include a vacuum chamber positioned on or near the outer surface of the handle 116. The vacuum chamber insulates the exterior of the handle from the extremely low operating temperature of the refrigerant moving through the handle to the cryoprobe 112. This may allow an operator to touch or otherwise manipulate the cryoprobe 112 during treatment.

[0053] The needle of the cryoprobe 112 may also include a heater positioned at or near the needle tip. The heater can be used to raise the temperature of the needle. The heater can be coupled to a control console and a suitable power supply disposed therein. The cryocontroller 104 can control the power signal delivered to the heater to raise the temperature of the needle. The temperature can be raised to a suitable ablation temperature in the range of about 70 degrees Celsius to about 100 degrees Celsius. In other examples, the ablation temperature can be about 80 degrees Celsius or higher. In yet another example, the ablation temperature can be about 90 degrees Celsius to about 100 degrees Celsius.

[0054] Although not shown, more than one cryoprobe 112 may be coupled to the console 102. Multiple cryoprobes 112 may be used in combination during a single cryoablation treatment. The console 102 may be configured to deliver refrigerant to each of the multiple cryoprobes 112. The cryoprobes 112 may be similar to each other or may be different from each other to produce ice balls of different sizes and shapes to freeze and destroy target tissue.

[0055] Now for reference Figure 2 Another exemplary cryoablation device 200 is illustrated. In this example, the cryoablation device 200 may include a cryoprobe 202 operatively coupled to a cryoablation control device 214. The cryoablation control device 214 may include a computing device such as a laptop computer, tablet computer, controller, programmable logic controller, smart device, etc. The cryoablation control device 214 may include a processor and memory. The memory may include executable instructions stored on the memory that may cause the cryoablation device 200 to perform the functions and / or methods described herein.

[0056] The cryoablation device 200 may include a refrigerant delivery device 210 and a cryoprobe monitor 212. The refrigerant delivery device 210 may include valves, pumps, and / or other refrigerant delivery equipment that can deliver refrigerant (e.g., liquid nitrogen) to the cryoprobe 202. The refrigerant delivery device 210 may be electrically coupled to and / or controlled by the computing device of the cryoablation control device 214. The refrigerant delivery device 210 may allow refrigerant to flow to the probe in the supply line 208 and to be removed and / or discharged from the cryoprobe 202 via the return or discharge line 216.

[0057] The cryoprobe monitor 212 can also be electrically coupled to the computing device of the cryoablation control unit 214. The cryoprobe monitor can be an electrical bus, data acquisition unit, computing device, control board, circuit, or other device that can receive cryoprobe operation information from the cryoprobe 202. The cryoprobe operation information can be, for example, temperature and / or impedance information obtained using sensors, thermocouples, temperature sensors, impedance sensors, etc. The cryoprobe operation information can correspond to the temperature and / or impedance obtained at one or more locations on or within the needle of the cryoprobe 202. The cryoprobe monitor 212 can provide the cryoprobe operation information to the cryoablation control unit 214.

[0058] The cryoprobe 202 may be similar to the cryoprobe 112 previously described. In this example, the cryoprobe 202 may include a heater 204 positioned within the needle 206 of the cryoprobe 202. In some examples, the heater 204 may be a resistance heater. The heater 204 may be coupled to a cryoprobe monitor 212. The temperature of the heater 204 and / or the needle 206 may be acquired by the cryoprobe monitor 212. The cryoprobe monitor 212 may also provide a power signal to the heater 204. The cryoprobe monitor 212 may include a power source or be coupled to a power source to provide the desired power signal to the heater 204. The cryoprobe monitor 212 may adjust, change, and / or modulate the power signal to the heater 204 based on the cryoprobe operation information previously described. The cryoprobe monitor 212 and / or the cryoablation control device 214 may adjust, change, or modulate a suitable power signal to the heater 204 so that the needle 206 of the cryoprobe 202 reaches the desired ablation or thawing temperature within a desired time period.

[0059] The cryoprobe that can be used in the cryoablation apparatus and method of this disclosure can have various structures. Figures 3 to 6 The cryoprobes shown illustrate some example cryoprobes. Figure 3The cryoprobe 300 illustrates an example of a cryoprobe. The cryoprobe 300 may include a needle or housing 302, a refrigerant supply source 304, and a heater 306. The housing 302 may be a tubular member including an outer wall forming an inner cavity in which various elements of the cryoprobe may be enclosed. In this example, the refrigerant supply source 304 may be centrally positioned within the inner cavity of the housing 302. The refrigerant supply source 304 may be a suitable conduit or tube that delivers refrigerant from the refrigerant source to the tip of the cryoprobe 300. The refrigerant can move towards the tip through the refrigerant supply source 304. The refrigerant can then flow out from the tip of the housing 302 through the space between the outer surface of the refrigerant supply source 304 and the inner surface of the housing 302. Through this flow, the refrigerant can remove heat from the target tissue positioned around the cryoprobe to freeze and destroy the target tissue.

[0060] Heater 306 may be positioned around refrigerant supply source 304. Heater 306 may be a resistance heater, which may include a resistance wire coil that heats when a power signal passes through heater 306. Heater 306 may have sufficient resistance to allow cryogenic probe 300 to be heated to a suitable temperature for cauterization. In some examples, this temperature may be greater than or equal to 80 degrees Celsius.

[0061] Heater 306 can be coupled to a refrigeration controller, which can control the power signal supplied to heater 306. Heater 306 can also be used by the refrigeration controller to measure one or more operating parameters or other operating information of the refrigeration probe 300. In some examples, heater 306 can be used to measure resistance, impedance, or temperature at one or more locations within the refrigeration probe 300. As further explained below, this information can be used to adjust or monitor the operation of the refrigeration probe 300.

[0062] Now for reference Figure 4Another cryoprobe 400 is shown. Cryoprobe 400 may be similar in many respects to the previously described cryoprobe 300. Cryoprobe 400 may include a housing 402, a refrigerant supply source 404, and a heater 406. The housing 402, refrigerant supply source 404, and heater 406 may be similar to the similar elements described above with respect to cryoprobe 300. In this example, cryoprobe 400 may additionally include one or more measuring points 408. Measuring points 408 may be coupled to a cryocontroller and may be used to measure one or more operating conditions of cryoprobe 400. In various examples, measuring point 408 may be a sensor, such as a thermocouple. In other examples, measuring point 408 may be other sensors or pads or contacts that can measure the resistance or impedance of cryoprobe 400 or tissue that may be located at or around cryoprobe 400. Measuring point 408 may be used to measure the resistance, impedance, temperature, or other characteristics of cryoprobe 400.

[0063] Now for reference Figure 5 An example cryogenic probe 500 is shown. The cryogenic probe 500 may be similar to the previously described cryogenic probe 300, and includes a housing 502, a refrigerant supply source 504, and a heater 506. The housing 502 and the refrigerant supply source 504 may be similar to the housing 302 and refrigerant supply source 304 previously described.

[0064] In this example, heater 506 may be a resistance heater with multiple coils. In this example, heater 506 may be positioned inside housing 502 and may be larger than the coils of heater 306. The diameter of the coils of heater 506 may be such that they are located at or near the inner surface of housing 502. Heater 506 may be configured to allow measurement of cryogenic probe operation information via a cryogenic controller or other data processing or data acquisition unit.

[0065] Now for reference Figure 6 Another example of a cryoprobe 600 is shown. In this example, the cryoprobe 600 may include a housing 602 and a refrigerant supply source 604. The housing 602 and the refrigerant supply source 604 may be similar to the housing 302 and refrigerant supply source 304 previously described. In this example, a heater 606 may be positioned on the exterior of the housing 602. In some examples, the heater may be enclosed around the housing 602, or it may be embedded in or fixed within the wall of the housing 602. The heater 606 may be a resistance heater formed of a coil of electrical wire. The heater 606 may be used to collect cryoprobe operational information regarding one or more conditions of the cryoprobe 600 or tissue.

[0066] Although not shown, it should be understood that in other examples, cryoprobes 300, 500, and 600 may include measurement points or other sensors, such as those described in example cryoprobe 400. Measurement points or sensors may be used to collect temperature, resistance, impedance, or other information about the operation of the cryoprobe.

[0067] As discussed above, the cryoprobe of this disclosure may include a resistance heater, which may be formed of a coil or a resistance wire of a certain length. Such a coil can be heated when a power signal is supplied to the heater. The housing or needle of the cryoprobe of this disclosure may have a small outer diameter, for example, in the range of about 1 mm to about 4 mm. With this sizing, the wire used to form the heater of this disclosure will have a very small diameter. The outer diameter of the wire may be less than 0.5 mm, less than 0.3 mm, or less than 0.1 mm. Because the heater that needs to be assembled inside or on the cryoprobe is extremely small, manufacturing variations, manufacturing defects, and / or damage that may occur during the production, transportation, and operation of the cryoprobe may have an increased impact on the operation of the heater.

[0068] Furthermore, in cryoablation procedures, it is desirable to perform the procedure without interruption or delay due to the impact of cryoablation on the patient. The cryoprobe and related methods disclosed herein allow for the rapid identification of any problems with the cryoprobe and heater. Even in the event of potential problems during cryoprobe use, the heater can continue to operate.

[0069] The heater of the cryoprobe disclosed herein may experience different types of problems during operation. In some cases, a short circuit may occur. For example, due to manufacturing defects, variations, or damage, the heater's wires may melt at the high temperatures used to perform ablation or other procedures during cryoablation. The heater's wires may partially melt and bridge one or more coils of the heater. This short circuit condition may allow the heater to continue operating after modification. In other cases, the heater may melt or break, and the heater may break or bridge to make conductive contact with the needle housing. This condition may prevent the cryoprobe from continuing to operate.

[0070] In other cases, the cryoprobe may experience an open circuit. The cryoprobe's heater may melt or break, compromising circuit continuity. In such cases, operation of the cryoprobe may need to be suspended. In other cases, the heater may experience partial melting or deformation, which may change the heater's resistance but allows continued operation under modified operating conditions. In still other cases, the heater may experience other problems or operational changes.

[0071] The cryoprobe and related methods of this disclosure can identify the aforementioned problems. In the context of this disclosure, the term "heater event" can be used to describe these problems, which may include short-circuit events, open-circuit events, heater damage events, heater melting events, etc. The cryoprobe and related methods of this disclosure can monitor the operation of the cryoprobe and heater to determine whether and / or when a heater event has occurred, and then take action to determine whether the operation of the cryoprobe can continue. In some cases, the cryoprobe can continue operation under modified operating conditions. This is an improvement over existing cryoprobes and methods that may fail to determine whether a heater event has occurred and, in some cases, may pause or delay treatment instead of being able to continue operation.

[0072] Now for reference Figure 7 Example graph 700 shows the resistance data and power signal of the cryoprobe heater. Graph 700 illustrates data that can be acquired from the cryoprobe during an example procedure in which the heater of the cryoprobe is energized. The heater can be energized to perform an ablation procedure during cryoablation treatment. The heater resistance graph 706 can be acquired, for example, by the cryocontroller based on the heater coil in the cryoprobe. The power signal graph 708 can be acquired, for example, by the cryocontroller based on the heater or based on a power supply coupled to the heater in the cryoprobe.

[0073] Graph 700 illustrates how heater operation can be monitored during a cauterization procedure (or other procedure where the heater of the cryoprobe is energized) to determine if and when a heater event occurs. In some examples, a baseline and one or more thresholds can be used to determine whether a heater event has occurred. In the example shown, the heater's resistance can be monitored and compared to a baseline resistance 724, an upper resistance threshold 722, and a lower resistance threshold 726. In this example, the baseline resistance 724 is approximately 12 ohms. In other examples, the baseline resistance 724 can be other values ​​depending on the heater's construction and / or materials. The upper resistance threshold 722 can be a value that allows the heater to operate without causing permanent damage to the heater. In one example, the upper resistance threshold 722 can be approximately 22 ohms. In other examples, other resistances can be used. The lower resistance threshold 726 can correspond to a value that allows the heater to still heat to the desired temperature level and / or does not indicate a short circuit, which could indicate that a power signal is being transmitted to the cryoprobe housing or the patient's tissue. In one example, the lower resistance threshold 726 can be approximately 2 to 5 ohms. In other examples, different lower resistance thresholds can be used.

[0074] like Figure 7As shown, heater resistance curve 706 illustrates an example burn-out process where a power signal is supplied to the heater. During the initial portion of the process, indicated by portion 702 of heater resistance curve 706 and portion 704 of heater power signal curve 708, the heater can operate normally, and the heater resistance can be at or near the baseline resistance 724. In portions 712 of heater resistance curve 706 and 710 of power signal curve 708, a heater event can be detected. The heater resistance may drop below the lower resistance threshold 726. This drop may indicate that a heater event has occurred, such as a short circuit. When such a heater event is detected, the refrigeration controller can initiate a recovery action to determine whether heater operation can continue. In the example shown and as indicated in power signal curve 708, the refrigeration controller can reduce the power supplied to the heater.

[0075] After the power is reduced, the resistance is continued to be monitored. In the example shown, the resistance can be seen to increase and then recover, returning to a level at or near the baseline resistance of 724. In this case, heater operation can continue. The temporary reduction in power supplied to the heater allows it to recover, enabling continued operation.

[0076] In section 716 of heater resistance curve 706, a second heater is even detected. In this example, the resistance again drops below the lower resistance threshold 726. Similarly, the refrigeration controller can reduce the power supplied to the heater. As shown in this example event, the heater does not recover and initially continues to decrease, then rapidly increases to a resistance level greater than the upper resistance threshold 722. Although the refrigeration controller continues to reduce the power supplied to the heater, the resistance remains above the upper resistance threshold 722. Such data or conditions shown in section 720 of resistance curve 706 and section 718 of heater power signal curve 708 can indicate that an open circuit condition has occurred in the heater (e.g., a permanent break or separation in the heater coil). When such a condition is detected, the heater cannot continue to operate because it will not function as intended. When such a heater event is detected, heater operation is suspended, and the refrigeration controller can issue an alarm or send a message to the user.

[0077] Understandably, graph 700 illustrates an example heater procedure where two heater events are detected, and if the heater is able to recover, the refrigeration controller attempts to continue operation. In other cases, other heater events may be detected, and / or if no heater events are detected, the refrigeration controller may continue operating the heater for multiple procedures.

[0078] In some embodiments of this disclosure, various parameters or indices may be used as alternatives to and / or in combination with the resistance and / or power values ​​of the cryogenic probe heater. Such parameters and indices may correspond to the resistance, temperature, power consumption, current usage, or other operating parameters of the cryogenic probe and / or heater. In various examples, a mean or average value may be used. A standard deviation may be used. Signal variation and / or a rate of change of signal may be used. Such parameters or statistics can be characterized by the following equations relating the operating parameter X of the heater and / or cryogenic probe.

[0079] Mean or average (expected value);

[0080] Standard deviation:

[0081]

[0082] Parameters and / or indices can be compared to known distributions or baseline distributions of such parameters and / or indices to determine when a heater event may occur. Various other indices can also be used, or alternatively, to detect heater events. In one example, the index / parameter data variation (IDV) can be used to detect heater events. IDV can be characterized using the following equation.

[0083]

[0084] In some embodiments, an index or parameter can be calculated using real-time operational information or current operational information (such as resistance, temperature, power, or current) of the cryogenic probe characteristics. The real-time index can be compared to a baseline index characterizing the expected operating condition of the heater. The expected operating condition can indicate that the heater can continue operating to perform a desired procedure, such as a defrosting cycle, a calcination procedure, etc. The real-time index can also be compared to a second, third, or other distribution, which may correspond to abnormal operating conditions, such as heater events (e.g., short-circuit events, open-circuit events, damage events, etc.). In one example, the second distribution may correspond to a short-circuit event, where the heater is able to recover after a reduction in power input, and the third distribution may correspond to a short-circuit event, where the heater is permanently damaged and cannot continue operating. The real-time data distribution can be compared to all distributions in the first distribution (normal operation), the second distribution (recoverable short-circuit event), and the third distribution (unrecoverable short-circuit event). By determining the overlap between the real-time distribution and each of the first, second, and third distributions, the cryogenic controller can determine what action to take to continue operation (if possible) or to abort operation.

[0085] The amount of overlap between distributions can be determined using the signal pattern function shown below, where m corresponds to real-time data computation and i corresponds to a predetermined data distribution (e.g., a first distribution, a second distribution, or a third distribution). Figure 8 A graphical depiction of the signal pattern function is shown 800. As shown, the signal pattern function below can determine the overlap, which corresponds to the real-time distribution area that overlaps with a predetermined data distribution in the predetermined data distribution of the heater event.

[0086]

[0087] In some examples, machine learning models can be used to determine or detect when a heater event has occurred. Machine learning models can also be used to determine what actions the refrigeration controller can take to continue heater operation and extend the lifespan of the refrigeration probe.

[0088] The term "model" or "machine learning model" as used in this disclosure includes data models created using machine learning and / or artificial intelligence. Machine learning may involve training a mathematical model in a supervised or unsupervised environment. Machine learning models can be trained to learn relationships between individual sets of data. These models may be based on a set of algorithms designed to model abstractions in the data using multiple processing layers. The processing layers may consist of nonlinear transformations. Machine learning models can include, for example, neural networks, convolutional neural networks, and deep neural networks. Such neural networks can consist of trainable layers of filters, transformations, projections, hashing, and pooling. These models can be used for large-scale relationship recognition tasks. These models can be created using a variety of open-source and proprietary machine learning tools and / or libraries known to those skilled in the art.

[0089] Now for reference Figure 9 An example machine learning model 900 is illustrated. The machine learning model can be used by a cryocontroller and can be part of one or more cryoablation devices of this disclosure. The machine learning model 900 can use one or more layers to process and / or identify complex, nonlinear, or other relationships between inputs and recommend outputs that allow the heater of the cryoprobe to continue operating. In the example shown, model 900 can utilize input 902, such as resistance, temperature, impedance, or other measurements performed during heater use. Input 902 can include the rate of change of measured parameters of the heater and / or cryoprobe. Input 902 can also include the parameters and exponents previously described. Further input 902 can include heater type, heater material, heater size, tissue type, tissue location, patient information, power signal characteristics, current measurement, modulation characteristics, etc.

[0090] Input 902 can be provided to model 900, and multiple layers of the model (such as input layer 904, hidden layer 906, and output layer 908) can provide output 910. Output 910 can include information about whether a heater event has occurred, the type of heater event, and / or trend predictions of heater operating parameters. Output 910 may also include recommended heating type, power signal modulation, power signal characteristics, etc.

[0091] This disclosure also considers various methods that can be performed by the heater, cryoprobe, and cryoablation device of this disclosure. In addition to the methods described above, the cryoablation device of this disclosure can be operated to extend the lifespan of the cryoprobe. Reference is now made to... Figure 10 An example method 1000 is shown. This method can be performed by cryoablation apparatus 100 or 200. Method 1000 is described as being performed by cryoablation apparatus 100, but it should be understood that method 1000 can be performed by other apparatuses.

[0092] Method 1000 may begin at step 1002. In step 1002, the refrigeration controller 104 may acquire refrigeration probe operation information. The refrigeration controller 104 may acquire the refrigeration probe operation information based on sensors or based on the heater coil of the refrigeration probe 112. The refrigeration probe operation information may characterize one or more operating characteristics of the refrigeration probe 112 and / or the heater. In various examples, the refrigeration probe operation information may be the resistance of the heater, the temperature of the heater, and / or the power or current supplied to the heater.

[0093] In step 1004, the cryocontroller 104 may compare cryoprobe operation information with one or more predetermined operation levels. The cryocontroller 104 may compare a real-time data distribution or a predetermined data threshold, a predetermined data distribution, or a predicted data distribution. As previously described, the comparison may include a comparison of data distributions and / or a comparison of calculated exponents or distributions with each other. In some examples, the cryoprobe operation information may be fed into a trained machine learning model.

[0094] In step 1006, the refrigeration controller may use the calculations and / or comparisons performed in step 1004 to determine whether a heater event has occurred. The comparisons may allow the refrigeration controller to determine whether a short-circuit event, open-circuit event, damage event, or other abnormal operation has occurred in the heater. If the refrigeration controller 104 determines that a heater event has occurred, method 1000 proceeds to step 1008. If the refrigeration controller determines that a heater event has not occurred, the method proceeds to step 1010.

[0095] In step 1008, the refrigeration controller may adjust the power signal supplied to the heater of the refrigeration probe. For example, the refrigeration controller may adjust the current or power of the power signal. Refrigeration controller 104 may modulate the power signal. In some examples, if a short-circuit event is detected, refrigeration controller 104 may reduce the power of the power signal. Refrigeration controller 104 may reduce the power of the power signal to determine whether the heater can recover from the event and continue operating. After step 1008, method 1000 may return to step 1002 to continue collecting refrigeration probe operation information to determine whether the operation of the refrigeration probe can continue. Although not specifically shown, in step 1006, the refrigeration controller may determine whether the heater has recovered from an earlier detected heater event. Method 1000 may continue monitoring the refrigeration probe operation information in a loop until it is determined that the heater has recovered or is operating within the normal range of operating parameters. If this is the case, method 1000 may continue to step 1010 after the heater has recovered. If, after the heater power signal has been adjusted in step 1008, a heater event continues to be detected in step 1006, the refrigeration controller can determine that the operation of the refrigeration probe should be stopped. If this occurs, the refrigeration controller 104 can issue an alarm or send a message to the user and shut down the heater.

[0096] In step 1010, since there are no heater events or the heater has recovered, the heater operates within the normal operating range. In step 1010, the refrigeration controller 104 can determine whether the heater program is complete. For example, this type of heater may correspond to a calcination program. If a predetermined temperature has been reached and maintained for a predetermined period of time, the refrigeration controller 104 can determine that the program is complete. In other examples, the refrigeration controller 104 may use other measurements or data thresholds to determine the completion of the heater program. If the refrigeration controller determines that the heater program is complete, method 1000 can end. If the refrigeration controller 104 determines that the heater program is not complete, the method can return to step 1002. The steps of method 1000 can be re-executed as described above to continue monitoring the heater performance and taking action when a heater event is detected until the heater program is determined to be complete in step 1010.

[0097] Referring now to FIG1100, an example computing device 1100 is shown. Cryoablation devices 100, 200 may include one or more computing devices 1100. For example, the cryoablation computing device and / or cryocontroller 104 of console 102 may have the elements shown in FIG1100. The cryoablation control device 214 of cryoablation device 200 may include one or more computing devices 1100. The computing device 1100 may perform the methods of this disclosure, such as method 1000, or may perform the steps of such methods.

[0098] As shown in the figure, computing device 1100 may include one or more processors 1102, working memory 1104, one or more input / output devices 1106, instruction memory 1108, transceiver 1112, one or more communication ports 714, and display 1116, all of which are operatively coupled to one or more data buses 1110. Data bus 1110 allows communication between various devices. Data bus 1110 may include wired or wireless communication channels.

[0099] Processor 1102 may include one or more different processors, each having one or more cores. Each of the different processors may have the same or different architecture. Processor 1102 may include one or more central processing units (CPUs), one or more graphics processing units (GPUs), application-specific integrated circuits (ASICs), digital signal processors (DSPs), etc.

[0100] Processor 1102 may be configured to perform a specific function or operation by executing code stored in instruction memory 1108, thereby embodying that function or operation. For example, processor 1102 may be configured to perform one or more of any functions, steps, methods, or operations disclosed herein.

[0101] Instruction memory 1108 may store instructions that can be accessed (e.g., read) and executed by processor 1102. For example, instruction memory 1108 may be a non-transitory computer-readable storage medium, such as read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, removable disk, CD-ROM, any non-volatile memory, or any other suitable memory.

[0102] Processor 1102 can store data in and read data from working memory 1104. For example, processor 1102 can store a set of working instructions in working memory 1104, such as instructions loaded from instruction memory 1108. Processor 1102 can also use working memory 1104 to store dynamic data created during operation of the cryoablation computing device of console 102. Working memory 1104 can be random access memory (RAM), such as static random access memory (SRAM) or dynamic random access memory (DRAM), or any other suitable memory.

[0103] Input / output device 1106 may include any suitable device that allows data input or output. For example, input / output device 1106 may include one or more of a keyboard, touchpad, mouse, stylus, touchscreen, physical button, speaker, microphone, or any other suitable input or output device.

[0104] The multiple communication ports 714 may include, for example, serial ports, such as a Universal Asynchronous Receiver / Transmitter (UART) connection, a Universal Serial Bus (USB) connection, or any other suitable communication port or connection. In some examples, the multiple communication ports 714 allow programming of executable instructions in the instruction memory 1108. In some examples, the multiple communication ports 714 allow the transfer (e.g., uploading or downloading) of data, such as cryoprobe operation information, resistance data, power data, temperature data, impedance data, etc.

[0105] Display 1116 may display user interface 1118. User interface 1118 enables a user to interact with the cryoablation computing device of console 102. For example, user interface 1118 may be a user interface that allows an operator to interact, communicate, control, and / or modify various messages, settings, or features that may be presented or otherwise displayed to the user. User interface 1118 may include sliders, dialog boxes, or other input fields that allow a user to control, communicate, or modify settings, limitations, or inputs used in cryoablation treatment. Furthermore, user interface 1118 may include one or more input fields or controls that allow a user to modify or control optional features or customizable aspects of the cryoablation computing device of console 102 and / or operating parameters of cryoablation device 100. In some examples, a user may interact with user interface 1118 using input / output device 1106. In some examples, display 1116 may be a touchscreen, with user interface 1118 displayed on the touchscreen. In other examples, display 1116 may be a computer monitor that can be interacted with using a mouse or keyboard. The user interface is an example of user interface 1118.

[0106] Transceiver 1112 allows communication with a network. In some examples, transceiver 1112 is selected based on the type of communication network in which the cryoablation computing device of console 102 will operate. Multiple processors 1102 are operable to receive data from or send data to a network, such as a wired or wireless network coupling the elements of cryoablation device 100.

[0107] The following is a list of non-limiting illustrative embodiments disclosed herein:

[0108] Illustrative Example 1: A cryoablation device includes: a cryoprobe including a heater and one or more sensors; and a cryocontroller including at least one processor and a memory, the cryocontroller being configured to: acquire cryoprobe operation information characterizing one or more operating characteristics of the heater; compare the cryoprobe operation information with a predetermined operating level of the heater to detect when a heater event occurs; and when the heater event is detected, adjust the power signal supplied to the heater.

[0109] Illustrative Example 2. The cryoablation apparatus according to Illustrative Example 1, wherein the heater is configured to raise the temperature of the cryoprobe to 80 degrees Celsius or higher.

[0110] Illustrative Example 3. The cryoablation apparatus according to any one of Illustrative Examples 1 or 2, wherein the one or more operating characteristics of the heater include the resistance of the heater.

[0111] Illustrative Example 4. The cryoablation apparatus according to any one of Illustrative Examples 1 to 3, wherein the heater is positioned inside the needle of the cryoprobe.

[0112] Illustrative Example 5. The cryoablation apparatus according to any one of Illustrative Examples 1 to 4, wherein the heater is positioned on or within the housing of the needle of the cryoprobe.

[0113] Illustrative Example 6. The cryoablation apparatus according to any one of Illustrative Examples 1 to 5, wherein the predetermined operating level of the heater includes an upper resistance threshold and a lower resistance threshold.

[0114] Illustrative Example 7. The cryoablation apparatus according to any one of Illustrative Examples 1 to 6, wherein the step of comparing the cryoprobe operation information with a predetermined operation level includes determining a cryoprobe operation index and comparing the cryoprobe operation index with one or more predetermined operation index distributions.

[0115] Illustrative Example 8. The cryoablation apparatus according to Illustrative Example 7, wherein the one or more predetermined operating index distributions include at least two predetermined operating index distributions.

[0116] Illustrative Example 9. The cryoablation apparatus according to Illustrative Example 8, wherein the at least two predetermined operating index distributions include a first predetermined operating index and a second predetermined operating index, the first predetermined operating index characterizing the baseline resistance of the heater, and the second predetermined operating index characterizing the resistance of the heater under short-circuit conditions.

[0117] Illustrative Example 10. The cryoablation apparatus according to any one of Illustrative Examples 1 to 9, wherein the heater event includes one of a short circuit condition, an open circuit condition, or a fault condition.

[0118] Illustrative Example 11. A cryoablation apparatus according to any one of illustrative Examples 1 to 10, wherein the step of adjusting the power signal supplied to the heater includes reducing the power signal to the heater when the heater event is determined to correspond to a short circuit condition.

[0119] Illustrative Example 12. The cryoablation apparatus according to Illustrative Example 11, wherein the cryocontroller is further configured to continue the operation of the heater when the cryoprobe operation information indicates that the heater has returned to a baseline operating state.

[0120] Illustrative Example 13. The cryoablation apparatus according to any one of Illustrative Examples 11 or 12, wherein the cryocontroller stops the operation of the heater when the cryoprobe operation information indicates that a heater malfunction has occurred.

[0121] Illustrative Example 14. A cryoablation apparatus according to any one of illustrative Examples 1 to 13, wherein the cryocontroller is further configured to send a notification when the cryocontroller detects that the heater event has occurred.

[0122] Illustrative Example 15. A method of operating a heater for a cryoprobe, comprising: acquiring cryoprobe operation information based on one or more sensors of the cryoprobe; comparing the cryoprobe operation information with a predetermined operation level of the heater to detect when a heater event occurs; and adjusting a power signal supplied to the heater when the heater event is detected.

[0123] Illustrative Example 16. The method according to Illustrative Example 15, wherein the step of comparing the cryoprobe operation information with a predetermined operation level includes determining a cryoprobe operation index and comparing the cryoprobe operation index with one or more predetermined operation index distributions.

[0124] Illustrative Example 17. The method according to Illustrative Example 16, wherein the one or more predetermined operating index distributions include at least two predetermined operating index distributions.

[0125] Illustrative Example 18. The method according to Illustrative Example 17, wherein the at least two predetermined operating index distributions include a first predetermined operating index and a second predetermined operating index, the first predetermined operating index characterizing the baseline resistance of the heater, and the second predetermined operating index characterizing the resistance of the heater under short-circuit conditions.

[0126] Illustrative Example 19. The method according to any one of Illustrative Examples 15 to 18, wherein the heater event includes one of a short circuit condition, an open circuit condition, or a fault condition.

[0127] Illustrative Example 20. The method according to any one of Illustrative Examples 15 to 19, wherein the step of adjusting the power signal supplied to the heater includes reducing the power signal to the heater when the heater event is determined to correspond to a short circuit condition.

[0128] The above description of the embodiments is provided for illustrative and descriptive purposes. It is not intended to be exhaustive or limiting of this disclosure. Various elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable where applicable and can be used in selected embodiments even if not specifically shown or described. The same may also apply to variations in many other respects. Such variations should not be considered a departure from this disclosure, and all such modifications are intended to be included within the scope of this disclosure.

Claims

1. A cryoablation device, comprising: A cryogenic probe, comprising a heater and one or more sensors; as well as A refrigeration controller, including at least one processor and a memory, is configured to: Acquire cryogenic probe operation information characterizing one or more operational characteristics of the heater; The cryogenic probe operation information is compared with the predetermined operation level of the heater to detect when a heater event occurs; and When the heater event is detected, the power signal supplied to the heater is adjusted.

2. The cryoablation apparatus of claim 1, wherein the heater is configured to raise the temperature of the cryoprobe to 80 degrees Celsius or higher.

3. The cryoablation apparatus of claim 1, wherein the one or more operating characteristics of the heater include the resistance of the heater.

4. The cryoablation apparatus according to claim 1, wherein the heater is positioned within the needle of the cryoprobe.

5. The cryoablation apparatus according to claim 1, wherein the heater is positioned on or within the housing of the needle of the cryoprobe.

6. The cryoablation apparatus of claim 1, wherein the predetermined operating level of the heater includes an upper resistance threshold and a lower resistance threshold.

7. The cryoablation apparatus of claim 1, wherein the step of comparing the cryoprobe operation information with a predetermined operation level comprises: Determine the cryoprobe operating index and compare the cryoprobe operating index with one or more predetermined operating index distributions.

8. The cryoablation apparatus of claim 7, wherein the one or more predetermined operating index distributions comprise at least two predetermined operating index distributions.

9. The cryoablation apparatus of claim 8, wherein the at least two predetermined operating index distributions include a first predetermined operating index and a second predetermined operating index, the first predetermined operating index characterizing the baseline resistance of the heater, and the second predetermined operating index characterizing the resistance of the heater under short-circuit conditions.

10. The cryoablation apparatus of claim 1, wherein the heater event includes one of a short circuit condition, an open circuit condition, or a fault condition.

11. The cryoablation apparatus of claim 1, wherein the step of adjusting the power signal supplied to the heater comprises: When the heater event is determined to correspond to a short circuit condition, the power signal to the heater is reduced.

12. The cryoablation apparatus of claim 11, wherein the cryocontroller is further configured to: When the freezing probe operation information indicates that the heater should return to the baseline operating condition, the operation of the heater should continue.

13. The cryoablation apparatus of claim 11, wherein when the cryoprobe operation information indicates that a heater malfunction has occurred, the cryocontroller stops the operation of the heater.

14. The cryoablation apparatus according to claim 1, wherein the cryocontroller is further configured to: When the refrigeration controller detects that the heater event has occurred, it sends a notification.

15. A method for operating a heater of a cryogenic probe, comprising: Based on one or more sensors of the cryoprobe, obtain cryoprobe operation information; The cryogenic probe operation information is compared with the predetermined operation level of the heater to detect when a heater event occurs; and When the heater event is detected, the power signal supplied to the heater is adjusted.

16. The method of claim 15, wherein the step of comparing the cryoprobe operation information with a predetermined operation level comprises: Determine the cryoprobe operating index and compare the cryoprobe operating index with one or more predetermined operating index distributions.

17. The method of claim 16, wherein the one or more predetermined operating index distributions comprise at least two predetermined operating index distributions.

18. The method of claim 17, wherein the at least two predetermined operating index distributions include a first predetermined operating index and a second predetermined operating index, the first predetermined operating index characterizing the baseline resistance of the heater, and the second predetermined operating index characterizing the resistance of the heater under short-circuit conditions.

19. The method of claim 15, wherein the heater event includes one of a short circuit condition, an open circuit condition, or a fault condition.

20. The method of claim 15, wherein the step of adjusting the power signal supplied to the heater comprises: When the heater event is determined to correspond to a short circuit condition, the power signal to the heater is reduced.

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